156 DAIRY BACTERIOLOGY 



damp and cold 1 . In the French soft cheeses Penicillium brevicaule 

 produces a taste of cabbage. 



The organisms which produce spongy cheese may also give rise 

 to unpleasant, mostly bitter-sweet tastes. Spongy cheeses, more- 

 over, dry too readily, so that they ripen too slowly. 



As cheese poisoning, like meat poisoning, is chiefly due to 

 certain colon bacteria and sometimes to non-motile butyric acid 

 bacteria, spongy cheese must always be regarded with suspicion 2 . 



1 At a low temperature the peptonising bacteria develop more rapidly 

 than the good lactic acid bacteria, or the bacterial metabolism may be too 

 sluggish to cause the disappearance of all the atmospheric oxygen in the 

 cheese. Sunlight promotes the oxidation of the fat in cheese, as in butter. 

 As already mentioned, copper salts and carbonic acid which latter is 

 copiously produced in the ripening of cheese, may turn the fat tallowy. 



2 H. Kuhl (" Zeitschrift f. Untersuchung der Nahrungs und Genuss- 

 inittel," 1913, Bd. 25, p. 193) reports on a case of poisoning by cheese 

 which was due to an aerogenes bacterium. A number of references to the 

 literature of this subject are given in this paper. 



